The 4.6mm PDW Compact was designed for a specific problem: creating a firearm small enough to be carried by people whose primary job is not shooting, but capable enough to defeat body armor when the shooting becomes unavoidable. The round's 21st-century ancestor, the 4.6x30mm, was developed for submachine gun platforms issued to vehicle crews and support personnel. By 2200 the cartridge has been refined into a fully caseless load — the combustible case leaves nothing to eject, which allows PDW platforms chambered for it to be built to dimensions approaching large pistols while maintaining a 40-round capacity. The projectile is a steel-penetrator design as standard; expanding variants exist but are considered secondary to the armor-defeat mission.

In GLMZ 2200, 4.6mm PDW Compact is the round of Arcturus Defense Solutions logistics and support contractors who get issued a weapon because regulations require it but are expected to never use it. It's also the round of mid-tier corporate security teams who need something that packs flat under a jacket and still handles armored threats. The Excluded have started acquiring PDW platforms in significant numbers — partly because they're compact and easy to conceal in settlement structures, partly because the round's armor-defeating capability is relevant when the threats are corporate enforcement teams in hard plate. Arcturus Defense Solutions produces the dominant load under contract; a commercial variant from Kovash Munitions is available retail at a meaningful quality reduction.